Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuinely useful behavioral context beyond them: daily granularity and the truncation limit ('most recent 90 samples'), which tells the agent the return is bounded.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences with zero waste; the resource and scope are front-loaded and the sample limit follows immediately. Nothing redundant or padded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter read tool with rich annotations and no output schema, the description covers purpose, granularity, and result size. Minor gaps remain (ordering, date semantics, whether samples are calendar-daily or scan-daily), but nothing critical is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with a single site_id documented as the site UUID, so the schema carries the parameter burden. The description adds no parameter-level detail beyond what the schema already provides, making baseline 3 appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Daily audit score history for a site') and clarifies the intent ('used for trend lines'). It is distinct from siblings like get_site_audit or get_audit_issues, though it doesn't explicitly name the sibling it differs from.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Used for trend lines' implies the usage context but gives no explicit when-to-use vs. alternatives or exclusions. An agent can infer it is for historical trending rather than point-in-time audit data, but nothing is stated directly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.